Tropical concrete construction



Aug. 21, 1934. 1 I 5. GRANT 1,970,561

TROPICAL CONCRETE CONSTRUCTION Filed Sept. 24. 1930 2 Sheets-Sheet 1 Aug. 21, 1934. J. E. GRANT 1,970,561

TROPICAL CONCRETE CONSTRUCTION Filed Sept. 24, 1950 2 Sheets-Sheet 2 11 I2 I I in Mimi f T: W u ml W? Patented Aug. 21, 1934 UNITED STA ':1-,,970,5V61" TROPICAL CONCRETE consrnoc'rron John E. Grant, Manila, Philippine Islands, as-

signor to Margaret T. Yates, New York, N.

Application September 24, 1930, Serial No. 484,019 a 4 Claims. I (0;. 7246) forms of an organic material are used and left in the finished product as a reenforcement.

A further object of my invention is the production of an organic form suitable for concrete construction.

system for forming a concrete structure.

A further object of my invention is the construction of a reenforced concrete structure embracing metallic reenforcing elements and in-organic forming and reenforcing elements.

A further object of my invention is an improved method for holding organic flexible structures in position to form forms for pouring concrete.

With the foregoing and other objects in view,

combination and arrangement of systems, apparatus and means as hereinafter specifically set forth and illustrated in the accompanying drawings wherein is shown the preferred embodiment of my invention, but it is understood that changes, variations and modifications may be resorted to which. come within the scope of the claims here'- unto appended.

- In order fully to understand my process of construction, I will now show details of the work. Fig. 1 is a sectional view taken. through 11 of Fig. 2; Fig. 2 is an enlarged view in elevation of the face of the form beforepo-uringthe material; Fig. 3 is a planview looking downward; Fig. 4 is an enlarged sectional view of a bamboo strand used in the mat construction; Fig. 5 is a sectional view of the corner of a building; Fig. 6 is a view in elevation of the construction shown in Fig. 5'; Fig. '7 is a'sectional view taken through 7-7 of Fig. 6; and Fig. 8 is a sectional view taken through 8-8 of Fig. 2 before'the supporting frame-work is removed.

Bamboo mats are constructed in sections of suitable size; I have found that mats 5 ft.,wide and 16 ft. long are convenient for construction for the side Walls; for the floors and roof much longer mats may be used to advantage. In the construction of these matsbamboostrands 16 ft. long form the horizontal members; and, when.

A further object of my invention is an improved my invention consists of the methods employed,

wish to be limited to the level, as these strands of the mat of which they are a. composition may be placed at anyangle with reference to the vertical thatthe construction may require, with reference to the side walls and partitions. In the floors, ceiling and roof the respective layers of bamboo mats are laid alternately cross-wise; i. e.,- one layer lengthwise of the building and the next layer cross-wise of the building I have found, however, that the nearer the horizontal, or level, the bamboo strands are placed the better bonding-I obtain, owing to the fact that there is less slip of the soft concrete. These bamboo strands are constructed as shown in cross-section in Fig. 3. The bamboo is split, the pulp removed-leaving the solid bamboo with the original outside shell or surface on the outside, the edges-being shaped to form angles to facilitate the bonding of the cement or plaster to the strand.- The warp is shown substantially in cross-se'ction as outlined in Fig. 3; in other words, it is not particularly shaped. Ido not wish to limit myself, however, to the shapes described and shown, asmy process and construction may be accomplished with almost any-shape laid up in "almost any way. I am describing, however, the preferable method as evolved in large building construction in the Philippine Islands.

The mats described are woven ordinarily by the natives by hand, Where the bamboo is worked. The construction is shown in detail in Figs. 1, 2 and 3. i To'form a wall two of these mats are placed back to back; that'is, the face or surface of the bamboo strands are outward on both sides. The mats are wired together at a specific distance apart, say from 3 tom inches, or more, according to whether they. are to be used as partition walls outside, or heavy supporting walls. This feature is particularly shown in Figs. 1-3, the wiring 10 spacing preferably being 'on 18 inch centers staggered.

Referring particularly to Fig. 8, the support ing studdingor temporary bracing, usually of 2 x 4 wood, is shown, there being placed between the mats and said bracing battens ofany suit-- able shape or size. I have found 1 x 3 to be suitable. 1 r a -'7 is a section of matte, and 8 is the bamboo strand. 9 is the bamboo warp. 10 are the tie wires. 11 are metal anchors. 12 are metal reenforcements. 14 is cement. 15 is concrete. 16 is the finished coat. 17 are battens, and 18' are braces. 1 Almost all varieties of bamboo growing in the that the thickness of the wall may require and held in place by 2 x as, or similar size of lumber. I have found that walls and columns. of sizes suitable for concrete bungalows can be poured continuously to a height of'l2ft. The vertical members of the supports are "placed approximately 2 feet on centers; the horizontal sup-.

ports being spaced approximately 3 feet apart.

These supports are placed equally on each side of the concrete wall to be poured, to support the bamboo mesh temporarily until theconcrete e e; mesh a d s p o re both. tiedby. w of s i ie t renetht pr v nt e pansion while the pouring of theconcrete takes place.

Theerection of the bamboo. mesh, as well, as the, supports for the same, requires but little skilled laborandti me, The filling of the space between thebamboomats with -concrete requires but little attention, as, any-voids can readily be detected, the mats being sufiiciently open to observe the density of the mixture.,, Practicallyno tamping is required; instead,,a little tapping, onthe outside of :the bamboomesh will cause the concrete to settle into properplace.

The surfaces of. the walls arealways accessible,

and can be-roughened to anynegree desiredibe fore-the concretesetsso as togleavethe surfaces of I the wall in the best possible condition to receive the plaster;materiahgtiles, or, aggregates,

! andobtain the best possibleadhesion. :The-cost of roughening the surfaces before the concrete sets isverysmall. .5

.The. mortarfrom; the concrete fills mostof, the voids in, the bamboo'mesh, causing the bamboo to beimbedded in;the;concr,ete tolsuch an extent that. the bamboo acts as a. very strong reenforcement. being. close ,to the. surface where it will have itsmaximum .value in tensile strength. Plaster is. applied to the outside surfaces, obtaining an excellent, mechanical; bond,.: as well as chemicalpas, a sufficient, amount of mortar from the concrete comes in contact with the plaster;

Ingthe setting up of the.mat...the horizontal strips of the bamboo meshareN-shaped, withthe point of the .V; ortheapex pointing inwardly,

thus causing the plaster to keyitselfto the .mesh. There are. also sufilcientvoids in the mesh after the concrete is poured to. proVideStillfurther means of mechanical bond. 1.

i The ordinary'system'requires the concrete to be roughened or. chipped after ,the' removal of the forms. The concrete is then set and hard and requires a great deal of time. and expense to place the surface of thewall improper condietionto receive-the plaster. material. This I avoid in my construction. T

Due to the cost andtime required by the ordinary system of construction, in many instances roughening is not properly done, which later 7 causes the plaster materials toseparate from the concrete. This ,I also avoid.

I would state that I am aware thatbamboo has been used-in the Philippines in some of the old churches for lathing using lime mortar, many of .which are: very old .also,;in. some .oldSpanish houses. The demolishing of these old buildings has found the bamboo to be in a perfect state of preservation.

Metallic reenforcing in the tropics, unless imbedded very deeply in the concrete, oxidizes and expands, breaking away the concrete to a great extent. A great many precautions need to be takento prevent this from occurring by making the concrete very dense and imbedding the reenforcing very deeply.

Metal lath has been practically disregarded, because of its rapid deterioration. Its intended use by the manufacturers, and the only practical value of the material, is to place the metal lath close to the surface of the concrete and plaster materials, and is worthless in the tropics, as suggested above.

Bamboo is not affected by moisture when imbedded under a properly mixed thin coat of cement mortar. Bamboo is abundant all over the Philippines and other tropic and semi tropic countries, and is very cheap. Mesh canbe made of bamboo material for less than half of the cost of metal lath and, in addition, transportation would not have to be considered, as the mesh couldbe made most anywhere there is likely to be construction work. r I

, In this type of bamboo construction, the waste of form lumber would be negligible, asthe only form lumber required would be the 2 x 4, supports for the mesh, which could be, used many dozens of times over again. Waste in form lumber, which is so great an item in concrete construction, would be entirely eliminated, especially in one-story structures. s

It has been proved by actual experience that my improved type of construction, in relation to the very costly placing. of forms of the ordinary system; the saving ofform, lumber; the small amount oflabor required to roughen the surfaces of the concrete walls; and the almost entire elimination of metal reenforcing,-will greatly reduce the-time and cost of concrete. COIlStIIlC-n.

tion for walls, columns, partitions, ceilings and other types of concrete construction. In the construction of columns, thexmats are formed in circular form-andsecured .inplace, then poured and worked as heretofore described in the formation of the side walls- .It may be well tohere describe the construction of 'a building, according to my method. First, the foundation of solid concrete is laid,.then the walls around and under the building are constructedto the first floor level. The floor is then laid, using closely woven very heavy bamboo the subjectmatter: of another application, a division of this application. The walls are now constructed to the ceiling level, then the ceiling is constructed almost the same as the floor the-subject matter of another application, a division ofthis application, both about 4 inches thick.

The roof is now placed in position. This con-' struetion is a little different the subject matter of another application, a division of this applicatlbn.

. I might state here that I have found it do-' sirable to begin my construction just above the ground levels, say 6 inches above. In the construction of columns and supporting pillars, I have deemed it advisable toreenforce the corners with iron, as shown in the drawings. See Figs. 5 and 6. In this specification and claims, I have been using the term, concrete and "concrete con-i structioni, rather loosely. I mean, generally,.a bondingmaterial. which may consist of hydrated cement, lime, or melted plastics; but I do not wish to limit myself to any bonding material. I wish especially to cover the mineral bitumens and asphalt as they are particularly applicable for my work in colder climates, or when stiffened with suitable stiffening materials.

Also, in this specification and claims, when I use the term, organic material", I have especially described bamboo; but grasses, bagasse, cornstalks, fibre, etc., are very suitable for my work.

In these specifications I have described the construction of bamboo mats. I wish it understood, however, that I do not limit myself to bamboo in this construction, as many other tropical fibers are useful in constructing mats for my forms; among these I might mention the sugar cane, cactus palms and reeds, and many other tropical plants. But I prefer the bamboo as being the larger and more easily worked.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. A wall construction comprising two opposed form members each consisting of two layers of split tropical fiber, said fiber being arranged with the larger arcuate surfaces outwardly and being closely arranged in staggered relation whereby to prevent the seepage of a filling material therethrough, a filling material of concrete within said forms, and a plastic coat on the outside and bonded to said tropical fiber forms.

2. A structure comprising two form members each consisting of layers of split fiber, said fiber being arranged with the larger arcuate surfaces facing the same side of the form and being closely arranged whereby to prevent an excess of seepage of a filling material therethrough, a filling material of consistency to fill said forms and to a limited extent ooze through said forms between said layers to bind with and form a coating on the exterior of said forms'whereby said forms are entirely encased in said materials.

3. A structure comprising two opposed form members each consisting of layers of fiber of split bamboo, said fibers being arranged with the larger arcuate surfaces outwardly and being closely arranged whereby to prevent an excess of seepage of a filling material therethrough, a filling material of concrete to fill said forms and to a limited extent ooze through said forms between said layers to bind with and form a coating on the exterior of said forms, and a bonding material on the exterior of said forms whereby said forms are entirely encased in said materials.

4. A structure comprising two form members each consisting of layers of split bamboo of substantial section, said bamboo being closely arranged whereby to prevent an excess of seepage of a filling material therethrough, a filling mate rial of consistency to fill said forms and to a limited extent ooze through said forms between said layers to bind with and form a coating on the exterior of said forms whereby said forms are entirely encased in said materials.

JOHN E. GRANT. 

